How to allow only certain files in Apache?

Serving images from another hostname  or Apache overload for the rewrites?

• We are trying to improve further the speed of some sites with older HTML in order as well to obtain better SEO results. We have now applied some minify measures, combined html, css etc. We use a small virtualized infrastructure and we've always wanted to use  a light + standar http server configuration so the first one can serve images and static contents vs the other one php, rewrites, etc. We can easily do that now with a VM using the same files and conf of vhosts (bind mounts) on apache but with hardly any modules loaded. This means the light httpd will have smaller fingerprint that would allow us to serve more and quicker, have more minSpareServer running, etc. So, as browsers benefit from loading static content from different hostnames as well, we've thought about building a rewrite rule on our main server (http://main.com) to "redirect" all images and css *.jpg, *.gif, *.css etc to the same at say http://cdn.main.com thus the browser being able to  have more connections. The question is, assuming we have a very complex rewrite ruleset already (we manually manipulate many old URLs for SEO) will it be worth? I mean will the additional load of main's apache to have to redirect http://main.com/image.jpg (I understand we'll have to do a 301) to http://cdn.main.com/image.jpg + then http://cdn.main.com having to serve it, be larger  than the gain we would be archiving on the browser? Could the excess of 301s of all images on a page be penalized by google? How do large companies work this out, does the original code already include images linked from the cdn with absolute paths? EDIT Just to clarify, our concern is not to do so much with server performance or bandwith. We could obviously employ an external CDN server but we have plenty CPU and bandwith. Our concern is with how to have "old" sites with plenty semi-static HTML content benefiting from splitting connections for images and static  content via apache without having to change the html to absolute paths (ie. image.jpg to http://cdn.main.com/image.jpg happening on the server not the  code)

• Answer:

  Have you considered using Nginx as reverse proxy to serve static content? You can do this without the rewrite rules on Apache. Check out http://cnedelcu.blogspot.com/2009/09/setting-up-nginx-as-reverse-proxy-on.html  for details on how this can be done. Using Nginx for load-balancing and reverse-proxying is pretty common practice in high volume/high traffic websites, so evaluate if it helps you.